Conventionally, fluidic devices that include a porous flow path member have been used for performing various operations such as separation, mixing, analyses, etc. of liquids. A detection agent can be contained in the flow path member of the fluidic devices. Therefore, the fluidic devices can be used as, for example, biochemical sensors for blood testing or DNA testing, or chemical sensors for quality control of foods or beverages.
However, fluidic devices have a problem that if an analyte liquid stagnates in the flow path member containing a detection agent, the detection agent spreads through the flow paths and smudges detection lines, etc. to make judgment difficult. Hence, it has been known to provide a fluidic device with an absorbent member for absorbing any excess analyte liquid. As an absorbent member for a fluidic device, for example, a highly absorbent fiber that is water-swellable to 10 times as large is known (see PTL 1). As another example of an absorbent member, a member that contains an absorbent core made of highly absorbent polymer particles is known (see PTL 2).
When the absorbent member gets exposed from the fluidic device, a hand may happen to touch it and may be contaminated with an analyte such as blood that is absorbed in the absorbent member. Hence, PTL 3 discloses that a protective coating film is provided over the layer for absorbing a fluid.